Acid nickel plating bath



United States Patent Ofiice 3,133,005 Patented May 12, 1964 3,133,005 AQH) NICKEL PLATEJ G BATH Barnet D. Ostrow, 125 Redwood Drive, and Fred I. Nobel, 75 Fern Drive, both of Roslyn, N.Y. No Drawing. Filed May 28, 1962, Ser. No. 197,860 6 Claims. (Cl. M L-49) various types of substances in conjunction with aromatic and aliphatic sulfonates, sulfonamids and sulfonimids. These prior suggested substances included alkynes, alkenes, amines, alkyne amines, and alkene amines. Such substances had in the molecule an allylic or vinyl group only, an acetylenic group only, or an active amino group only. It has also been proposed to incorporate compounds having in the same molecule an amino and an allyl or vinyl group.

While some addition agents accomplished this purpose in some degree, they did not contribute to superior leveling coupled with the ease of control. Also, because of the high concentration of these compounds that were necessary to produce the desired brightness and leveling the ductility was impaired. In some cases as with the alkynols the deposit has a marked tendency to skip plate, i.e. to prevent deposition of nickel at the-low current densities.

The present invention has among its objects to introduce additives, for the above purpose, into aqueous acid nickel plating baths, which will result in excellent leveling of the deposit.

It is also among the objects of the invention to provide a bath for the purpose described which will reduce the low current density skip plate in the deposited film of nickel.

In practicing the invention, there is provided the usual aqueous acid nickel plating bath and there is incorporated therein an additive which consists of at least one compound which contains in the same molecule. an amino, an alkyne, and an alkene group. Substances having these three groups impart superior leveling characteristics to the bath, with a substantial improvement in low current density characteristics of the nickel deposit. Relatively small amounts of these substances are very effective, and they do not impair the ductility of the deposit.

These substances have the following structural forwherein R is an alkene group; R is an alkyne group; R and R are alkene, alkyne, H, CH C H C H phenyl and naphthyl and X is an acid group, such as halogen, SO H, or P0 Compounds (C) and (D) may be quaternized.

While alkene and alkyne carbon chains up to 8 carbon atoms may be present in the molecule, at present the lower carbon chains are considered to be more desirable. Together with the substances of the invention, the structural formulas of which are given above, other acetylenic compounds may be incorporated into the bath, thus employing a mixture of unsaturated compounds.

The structural formulas given below are illustrative of the substances included in the invention.

HCEC-CH2NCH2OHECH2 Allyl propargyl amine (2) CH2CH=CH HCEC-CH2N OHgCH=CH2 Diallyl propargyl amine CH2CH=CH2 nozo-om fi-onzon=orn CHzCH=CHn Triallyl 'propargyl amine The essence of the invention lies in the structures of the additives in which there are combined in a single molecule, the amino, alkyne and alkene radicals. The deposits resulting from baths containing these additives have high lustre and are smooth with excellent leveling. In addition, the deposits do not exhibit low current density greyness which often occurs when additives such as amines or polyamines are used in the bath.

Compounds of the present invention may be used singly or in mixtures or in the absence of other types of additives. They may be used in standard Watts baths, all chloride baths, or high chloride baths. Improved results are obtained where there is incorporated therewith in the bath a sulfonic acid, sulfonarnid or sulfonimid.

Typical standard nickel baths which are employed in the invention are as follows in grams per liter.

Watts bath:

NiSO .7H O -400 NiCl .7H O 5-80 Wetting agents 0-1 Boric acid 5-60 All chloride bath:

NiCl .7H O 50-200 Boric acid 0-50 Wetting agent Among typical wetting agents are sodium lauryl sul fates, sodiumZ-ethyl hexyl sulfate, and sodium octyl sulfonic acid. The range of pH is from 2.5 to 4.5 in usual practice.

The following are specific examples of baths according to the invention which are employed to obtain bright, level and ductile deposits; the amounts being in grams per liter of aqueous solution:

Nickel Sulfate Nickel Chloride Boric Acid. Saccharin Bromo BBHTQHB Sulfonate 1,5-Benzene Dislllfonate Vinyl Ben-".ene Sulfonate Sodium Allyl Sulfonate Sodium Ben ialdehyde Sulfona Dibenzene sulfonamid Allyl sulfonamid B-Diallyl amino propyne-l Triallyl propargyl amine chloride- 1-Al1yl3-amino dipropyne l-Allyl amino 2-buty-ne.

Allyl propargyl amine pH 3. 6 4. 0 Temp, F 140 135 Examples of amino vinyl acetylenic compounds are as follows:

The following sulfonic acids may be incorporated in the bath with the principal additive; they may be in the form of salts, such as of nickel, sodium, magnesium, etc.

Benzene sulfonic acid Di-benzene sulfonic acid Vinyl benzene sulfonic acid Allyl benzene sulfonic acid Bromo benzene sulfonic acid 1,5-naphthalene disulfonic acid 1,3,6 naphthalene trisulfonic acid Among the sulfonamids and sulfonimids which are suitable are the following:

Saccharin Na salt Benzene sulfonamid Dibenzene sulfonamid Allyl sulfonamid The baths of the invention may be operated over a wide range of concentration, pH, and current densities. A pH range of 3.0 to 4.8 is typical. The concentration of the additive may vary from about .001 to .50 gram per liter when used with cooperating sulfo oxygen type materials. The concentration of the sulfo oxygen will generally determine the concentration of the alkene-alkyne amine. When used alone, the concentration of the alkenealkyne amine generally ranges from about .001 to 1.0 gram per liter.

These baths may be operated with or without mechanical or air agitation. When air is used, a compatible lowfoaming or non-foaming type of wetting agent is employed in the bath; The invention may be used in all sulfate baths, that is baths substantially free from chlorides; and it is suitable for sulfamate baths also.

We claim: a

1. An aqueous acid nickel electroplating bath having incorporated therein an amine having as substituent groups an alkene and an alkyne radical attached to nitrogen and having the following structural formula:

I'M B1-N-R3 wherein R is an alkene group and R is a radical taken from the class consisting of alkene, alkyne, H, and lower alkyl, and R is alkyne.

2. An aqueous acid nickel electroplating bath having incorporated therein an amine having as substituent groups an alkene and an alkyne radical attached to nitrogen and having the following structural formula:

wherein R is alkene, R is alkyne, and R and R are taken from the class consisting of alkene, alkyne, H, and lower alkyl, and X is an acid group.

3. An aqueous acid nickel electroplating bath having incorporated therein an amine having as substituent groups an alkene and an alkyne radical attached to nitrogen and having the following structural formula:

wherein R is alkene, R is alkyne, and R and R are taken from the class consisting of alkene, alkyne, H, and lower alltyl.

4. An aqueous acid nickel electroplating bath having incorporated therein an amine having as substituent groups an alkene and an allcyne radical attached to nitrogen, and having the following structural formula:

terized in that said compounds are quaternized.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3, 133,006 May 12 1964 Barnet D. Ostr'ow et a1"- that error appears in the above numbered pat- It is hereby certified that. the said Letters Patent should read as ent requiring correction and corrected below.

Column 2, lines 9 and 10, formula (1) should appear as shown below instead of as in the patent:

Signed and sealed this 29th day of December 1964,

(SEAL) Attest:

EDWARD J. BRENNER ERNEST W. SWIDER' Attesting Officer Commissioner of Patents 

1. AN AQUEOUS ACID NICKEL ELECTROPLATING BATH HAVING INCORPORATED THEREIN AN AMINE HAVING AS SUBSTITUENT GROUPS AN ALKENE AND AN ALKYNE RADICAL ATTACHED TO NITROGEN AND HAVING THE FOLLOWING STRUCTURAL FORMULA: R1-N(-R4)-R3 WHEREIN R1 IS AN ALKENE GROUP AND R4 IS A RADICAL TAKEN FROM THE CLASS CONSISTING OF ALKENE, ALKYNE, H, AND LOWER ALKYL, AND R3 IS ALKYNE. 